In mixed signal integrated circuits, such as a System on Chip (SOC) circuits, multiple functional circuit blocks are integrated in a single chip. Mixed signal integrated circuits include both digital and analog circuits on the same chip. For example, a single chip may include an analog-to-digital converter, analog signal conditioning circuitry, digital signal processing circuitry, digital signal communication circuitry, etc.
In mixed signal integrated circuits, spurs caused by switching in the digital circuits may be induced in the analog signals present in the circuit. For example, switching transients in digital Metal Oxide Semiconductor (MOS) circuits may be coupled to analog circuits integrated on the same die through ground, power supplies, or the substrate of the integrated circuit. If the spurs due to digital switching lie in the band of interest of an analog circuit, the spur can degrade the performance of the analog circuit.